Semiconductor Photonics is the study and application of photonic systems which use a semiconductor, such as silicon, as an optical medium. The semiconductor is usually patterned with sub-nanometer precision, into components that may operate in the infrared wavelengths, used by most fiber optic telecommunication systems. The semiconductor typically lies on top of a layer of silica, also known as silicon on insulator (SOI) fabrication, and is packaged into a photonics die.
The photonics die receives light from a continuous wavelength laser. This laser light source can be either physically attached to the photonics die delivering light directly to the phonics die or be positioned separate from the die. When off-die lasers are used, light from the laser can be fed into the photonics die by the use of glass fibers or other waveguide materials such as a polymer. Light thus introduced into the photonics die waveguide input becomes encoded data, by electronically modulating the light in the form of optical pulses. The optical pulses pass through additional optical components and finally to a waveguide output that may transmit, light pulse data to an adjacent optically connected device or a different photonics system.